Human Error Behind Drugchu Mudslide Tragedy
January 28, 2011
Drugchu exploited its mountains, its water and its rivers and, in return, suffered a powerful mudslide
Over 1,239 people were killed and more than 505 went missing in the disaster.
Jiang Gaoming, the chief researcher at the Chinese Academy of Sciences' Institute of Botany, listed three major factors - indiscriminate deforestation and building of hydropower dams and construction of residential houses near river courses - which compounded the disaster.
"The area was known for its forests, rich water resources, fertile land and pleasant climate. But after the felling of tens of billions of cubic meters of timber and the construction of huge numbers of hydropower dams, the area's hill have been left barren and unable to absorb rainfall," he said.
Mr Jiang corroborated his findings with statistics of the region's forest cover. "Drugchu county, known for its rich vegetation, has 65% or 1,940 square kilometers land available for forestry. Of this, 820 square kilometers, or 45% was actually forested, a higher percentage than the natural average of 22%. Unfortunately, these forests have been decimated by three decades of felling. In the 1970s, 80,000 cubic meters of lumber were already being chopped down annually. Unchecked tree felling and trading eventually led to the county's forestry resources diminishing by 100,000 cubic meters per year," he said.
"Following last August's devastating mudslide, reporters noted that the hillsides above the Sanyan valley, one of the worst areas, were bare of trees and even the brush was sparse. Without the vegetation, heavy rain was able easily to loosen soil and stones, triggering landslides that threatened lives and property below," he added.
Secondly, widespread construction of hydropower dams along with the rampant deforestation has contributed to the area's vulnerability. "As many as one thousand large and small dams were built on the main Bailong river with no thought given to upstream ecologies, such projects have increased the likelihood of mudslides. The Bailong flows through a zone that is prone to earthquakes and the quarrying of stone from the banks of the river to build the dams has further destabilised the hillsides," Mr Jiang said.
He further noted that hydropower construction often conflicts with environmental protection goals. "Dam-building has led to the destruction of forest reserves, for example, and intervention by the forestry authorities is rarely effective," he said.
"Between 2003 and 2007, contracts for 53 hydropower projects were signed in Drugchu. Forty-one of these have since been built or are now under construction and the remaining 12 will soon follow. Together, they account for 80% of the county's development projects. It is estimated that the under construction of forty-one dams will result in the dredging of 38.3 million cubic metres of sediment and the loss of 749,000 tonnes of soil. On completion of a dam, water soaks the hillsides and loosens the earth, creating a situation where landslides could happen at any time. The dredging of sand also leaves the river bed covered in rocks which can be swept away by floodwaters, making those floodwaters much more dangerous," he said.
The third major problem is the lack of urban planning and construction of residential houses near river banks. "Although mudslides and landslides have raised awareness of the dangers among local people, there is still a lack of urban planning and construction is still happening in vulnerable areas. The narrow valley floor on which Drugchu lies is just 12 square kilometres in area. The population has been growing for decades, and the only place left to build is the river banks. Property developers see the Sanyan and Luojia rivers as their only option and have been buying up land for construction," Mr Jiang said.
"The riches of economic development are not as valuable as green mountains and clear rivers. And it is ordinary, local people who are left to endure the impacts of environmental disasters. The suffering in Drugchu is environmental suffering. It is time for an approach to human development that avoids putting environment, lives and property at risk simply for the sake of economic growth," Mr Jiang concluded.
(Note: Researcher Jiang Gaoming used "Zhouqu" as the Chinese name for Drugchu in his article) Back to Archived Reports List
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